feat(models): sd_org_settings add agent_config column (was runtime ALTER only)

models/sd_org_settings.json

@@ -12,6 +12,7 @@
         {"name": "org_id", "title": "组织ID", "type": "str", "length": 32, "nullable": "no"},
         {"name": "workspace_root", "title": "工作空间根路径", "type": "str", "length": 500, "nullable": "no"},
         {"name": "skills_dir", "title": "企业Skills目录", "type": "str", "length": 500},
+        {"name": "agent_config", "title": "Agent配置JSON", "type": "text"},
         {"name": "created_at", "title": "创建时间", "type": "timestamp", "nullable": "no"},
         {"name": "updated_at", "title": "更新时间", "type": "timestamp"}
     ],